package 第3周_数据结构基础.第2章栈和队列.Stack;

import java.util.Stack;

public class Solution {
    public static boolean isValid(String s){
        Stack<Character> stack = new Stack<>();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '(' || c == '[' || c == '{'){
                stack.push(c);
            }else {
                if (stack.isEmpty()){
                    return false;
                }

                char topChar = stack.pop();
                if (c == ')' && topChar != '('){
                    return false;
                }
                if (c == ']' && topChar != '['){
                    return false;
                }
                if (c == '}' && topChar != '{'){
                    return false;
                }
            }
        }
        return stack.isEmpty();
    }

    public static void main(String[] args) {
        System.out.println(isValid("()[]{}"));
    }
}
